Polish Ring-billed Gull tracked through Europe
A regularly returning Ring-billed Gull that was recently fitted with a satellite transmitter in Poland has migrated west in recent weeks.
The bird, known as 'Kajzerka', was originally caught and ringed as an adult in Szczecin in 2005, and has been observed regularly over the years throughout Poland, generally during the late autumn and early winter period before disappearing. However, it had rarely been seen anywhere but Poland, despite the presence of a distinctive red darvic ring.
Graph showing the movements of Kajzerka from Poland to The Netherlands in December 2021 (Marcin Faber / Interrex).
In early December 2021, Kajzerka was again trapped in north-east Poland and fitted with a GPS transmitter in order to better understand its movements.
However, poor weather and short daylight hours meant that the tag only emitted a few GPS fixes in the first couple of weeks of its use – north of Szczecin on 7-8 December, and then in the Elbe valley west of Berlin, Germany, on 22 December.
Then, on Christmas Day, two pointers were collected, putting Kajzerka in The Netherlands, where it appeared to be on active migration, covering close to 200 km in a south-westerly direction in a four-hour gap between the tag's transmissions.
On 27th, the bird had moved further south-west and into Belgium, where it was seen to the south of Antwerp. It was seen again on the evening of 28th – this the second time the bird has been seen in the country, following a few weeks' stay in February-March 2012. It remains to be seen whether Belgium is Kajzerka regular wintering haunt or it continues westward.
The bird's movements highlight just how easily a vagrant bird can range widely (and, presumably for many years) in a relatively well-birded area of the world and still not be seen by birders.
Further details on this bird and updates to its movements will be reported at the Interrex Facebook page.